2024 GMC Sierra power train problems

“My truck has experienced recurring diagnostic trouble code P244B on [XXX], [XXX], and [XXX], 2026. The latest occurrence included a check-engine warning and reduced engine power. On [XXX], at 40,833 miles, Neil Huffman Chevrolet GMC in Frankfort, Kentucky, diagnosed a damaged diesel particulate filter differential-pressure sensor connector. The dealership's written estimate states that the connector had shorted, begun melting, and had broken wires at the back of the connector. I am concerned about the cause of the electrical overheating, the possibility of additional wiring damage, and the risk of unexpected reduced engine power while driving. I have also experienced intermittent transmission-related warnings and communication fault codes, although I do not know whether these problems are related. I understand there are GM technical bulletins addressing wiring-harness damage on certain 3.0L Duramax vehicles. I am not claiming these bulletins establish the cause of my failure, but I would appreciate having my experience evaluated for a possible safety-related defect trend.”

“Driving at approximately 45 mph on Berthod Pass in CO, towing a snowmobile flatbed trailer, when dash display indicated "low oil pressure, Turn off Engine". By the time I could read that, the engine was already off and I was all over the road trying to find a way to get off the highway. I did not have opportunity to get off highway, and ended up against a barrier, and partially remaining in traffic. GM towed the car (not the trailer, I had to do that myself) to a dealer quite some distance from my home as opposed to the dealer where I purchased the truck. Then they told me they towed it to a different dealer. After recovering my stuff, I went to the dealer where the truck was, and they said they couldn't look at it for several days. I could not wait several days simply to find out it was going to be a couple of months before id have the truck back. I traded it in on another, larger GMC simply to get out of that engine. What I learned though, is that GM used that exchange to make about $20K. This was more the dealer, but they are part of GM. My original truck was priced below book, and not the book the public can see, but the book they say they go by. They paid…”

“At approximately 2 years, 47,000 miles I received a message that I needed to service the transmission soon. I then got a message "Trailer Brakes Disabled Service Required" and another "Service Transmission Now Unable to Shift Soon". I brought the vehicle into my closest GM dealer and they said it is a faulty shift control lever. These are known to have a fault from the factory, but since I am outside of the 36,000 bumper to bumper, they will not cover the cost. It took about 2 months for the part to come in as it was on back order, and now they want $1000 to replace it.”

“The contact owns a 2024 GMC Sierra 1500. The contact stated that while driving 55 MPH, the message "Reduced Acceleration" was displayed and the vehicle decelerated quickly, and the contact was forced to pull over to the side of the road. The vehicle was taken to the dealer on several occasions to be diagnosed. During the first visit, the dealer stated that a transmission error code was retrieved and was cleared before the vehicle was returned. During the second visit, the dealer stated that the engine was consuming an excessive amount of engine oil and recommended that the engine be replaced. The contact stated that the message "Reduce Acceleration - Drive with Care" was displayed, and the vehicle went into LIMP Mode. Occasionally, after shifting to drive(D), the engine revved but the vehicle failed to respond, and the vehicle was taken back to the dealer. The manufacturer was notified of the failure. The failure mileage was 74,200.”

“I purchased a 2024 GMC Sierra 1500 Denali VIN # [XXX] on XXX with approximately 18,599 miles on the vehicle. The incidents are identified below in order. 1) XXX, Vehicle engine failure while driving at high speeds, with my daughter as a witness. I Reported the incident to Elder Ford on XXX, and my sales associate told me to take it to GMC for factory warranty. XXX took the vehicle to Central Buick GMC they performed a test that found no codes and replaced the fuel Pump Module from past experiences. They let me take the vehicle home. 2) XXX Vehicle engine failure while driving at high speeds, had to get it towed to the dealer for repair. Again, they found no codes. Had it for 5 days. Made me take it home. 3) Picked it up on XXX , was driving home and the same thing happened while going 70+ mph on the interstate. Stalled again. Drove it back to the dealer and dropped it off again, same day on the XXX. 4) Again, they found no codes and made me pick it up on XXX I was driving home on XXX and the same thing happened- lost complete power while going down the road at 40+ MPH. I had to get it towed the same day back to the dealer where it currently is at.”

“Lifters and camshaft failure, loud clanking, & sudden power loss on the 6.2 motor are the first noticeable signs. Instantly when everything happened check engine light, cruise control, & stabilizer lights flashed. The sudden loss of power forced the vehicle to suddenly slow down forcing my camper into the truck. I was hauling a within weight standerd camper but had difficulty bringing both the truck with the camper to a safe stop. There were no early signs or signal prior to sudden cautostrophic engine failure & all service records have been completed by a GM certified service dealer.”